Joint Commission survey questions and answers.
Explore the source record for details and available documents.
Accreditation↗
Biomedical subjects
D Williams
Publications and source records attributed to D Williams.
A stain on the stainless? The role of steels in the new age.
Some recent events have suggested that the best days of steels have gone and that disposable plastics would be better for many applications. Although it cannot be denied that plastics have taken over many of the roles of steel during the last few decades and will, quite rightly, continue to do so in certain areas, this article argues the case for proper consideration for steels in other areas, where their properties are still of the greatest relevance.
Equipment Design↗
Small is beautiful: microparticle and nanoparticle technology in medical devices.
An increasing number of technologies require the production of ultra-small spherical particles, often described as micro-spheres or nano-spheres. They may be used for a variety of medical applications from cell encapsulation to serological diagnostic procedures. This article discusses some of the principles of this technology.
Equipment Design↗
Inter-relationships between small, dense low-density lipoprotein (LDL), plasma triacylglycerol and LDL apoprotein B in an atherogenic lipoprotein phenotype in free-living subjects.
A predominance of small, dense low-density lipoprotein (LDL) is a major component of an atherogenic lipoprotein phenotype, and a common, but modifiable, source of increased risk for coronary heart disease in the free-living population. While much of the atherogenicity of small, dense LDL is known to arise from its structural properties, the extent to which an increase in the number of small, dense LDL particles (hyper-apoprotein B) contributes to this risk of coronary heart disease is currently unknown. This study reports a method for the recruitment of free-living individuals with an atherogenic lipoprotein phenotype for a fish-oil intervention trial, and critically evaluates the relationship between LDL particle number and the predominance of small, dense LDL. In this group, volunteers were selected through local general practices on the basis of a moderately raised plasma triacylglycerol (triglyceride) level (>1.5 mmol/l) and a low concentration of high-density-lipoprotein cholesterol (<1.1 mmol/l). The screening of LDL subclasses revealed a predominance of small, dense LDL (LDL subclass pattern B) in 62% of the cohort. As expected, subjects with LDL subclass pattern B were characterized by higher plasma triacylglycerol and lower high-density lipoprotein cholesterol (<1.1 mmol/l) levels and, less predictably, by lower LDL cholesterol and apoprotein B levels (P<0.05; LDL subclass A compared with subclass B). While hyper-apoprotein B was detected in only five subjects, the relative percentage of small, dense LDL-III in subjects with subclass B showed an inverse relationship with LDL apoprotein B (r=-0.57; P<0.001), identifying a subset of individuals with plasma triacylglycerol above 2.5 mmol/l and a low concentration of LDL almost exclusively in a small and dense form. These findings indicate that a predominance of small, dense LDL and hyper-apoprotein B do not always co-exist in free-living groups. Moreover, if coronary risk increases with increasing LDL particle number, these results imply that the risk arising from a predominance of small, dense LDL may actually be reduced in certain cases when plasma triacylglycerol exceeds 2.5 mmol/l.
Adult↗
Sulfasalazine treatment for rheumatoid arthritis: a metaanalysis of 15 randomized trials.
OBJECTIVE: To assess the efficacy and safety of sulfasalazine (SSZ) compared to placebo and other disease modifying drugs. METHODS: A metaanalysis was performed on 15 randomized clinical trials of rheumatoid arthritis (RA) that included SSZ (2 g/day average dose, 36 weeks average followup) as a treatment. Eight trials included a placebo group (PL), 2 hydroxychloroquine (HCQ) (350 mg/day average dose), 3 D-penicillamine (D-Pen) (667 mg/day average dose), and 4 gold sodium thiomalate or aurothioglucose (GST) (25 mg, 1 g/wk). RESULTS: Compared to PL, SSZ was superior for improvement in erythrocyte sedimentation rate (ESR) (SSZ 37%, PL 14%; p < 0.0001), morning stiffness duration (SSZ 61%, PL 33%; p = 0.008), pain visual analog scale (SSZ 42%, PL 15%; p < 0.0001), articular index (SSZ 46%, PL 20%; p < 0.0001), number of swollen joints (SSZ 51%, PL 26%; p < 0.0001), number of painful joints (SSZ 59%, PL 33%; p = 0.004), and patient global assessment (SSZ 26%, PL 14%; p = 0.02). Withdrawals from study because of adverse drug reactions were increased (SSZ 24%, PL 7%; p < 0.0001), but lack of efficacy dropouts were decreased (SSZ 8%, PL 21%; p < 0.0001). Compared to HCQ, SSZ tended to have fewer lack of efficacy dropouts (SSZ 5%, HCQ 15%; p = 0.055) and improved ESR (SSZ 43%, HCQ 26%; p = 0.10) and morning stiffness duration (SSZ 59%, HCQ 40%; p = 0.09). Compared to GST, adverse drug reaction dropouts were significantly fewer (SSZ 12%, GST 29%; p < 0.0001), while withdrawals due to lack of efficacy were greater (SSZ 13%, GST 4%; p = 0.006). More patients tended to complete treatment taking SSZ (SSZ 69%, GST 61%; p = 0.09). CONCLUSION: Over all, the metaanalysis provides data that support the effectiveness of SSZ as a treatment for RA.
Antirheumatic Agents↗
Research into practice?
Explore the source record for details and available documents.
Evidence-Based Medicine↗
The parting of the ways? How biomaterials may differ from advanced materials in the next century.
A recent symposium on the future role of materials science in some critical industries suggests that the historical reliance of the medical device industry on the advances made in conventional materials development may not be sustained in the next few decades.
Biocompatible Materials↗
Great expectations and the grapes of wrath: contamination of contact lenses.
The results of an analysis of complications in contact lens wearers in The Netherlands indicate that there is an increased risk of keratitis associated with the extended wear of the lenses. This article discusses some of the underlying issues.
Biocompatible Materials↗
Population review of 1998: England and Wales.
This article outlines the main features of the population of England and Wales in 1998. Where 1998 figures have not yet been produced, data for the latest available year are given.
Abortion, Induced↗
The stresses and strains of everyday life.
Stresses and strains are features of everyday living, but the distinction between the two is not always easy to identify. These matters are discussed in mechanical and physiological terms with relevance to medical devices.
Biomedical Engineering↗
The god of small things: the biology of intimal hyperplasia.
One of the most significant, and as yet unresolved, consequences of placing devices within the vascular system is the uncontrolled growth of the inner layer of the bloodvessel wall following contact with the device. This process is one of the most difficult challenges facing all aspects of intervention; it confronts techniques such as renal-artery stenting, vein grafts, balloon angioplasty, endarterectomy and atherectomy. This article discusses some of the proposed mechanisms for this phenomenon and the prognosis for its control.
Arterial Occlusive Diseases↗
Conflict resolution and Y2K problems. How biomaterials will face up to the real issues of the future.
At the end of this century, the medical device industry has achieved some notable successes, yet achieves so little in terms of significant functional replacement and reconstruction of the body. This is partly because of the materials that are used. This article addresses the main points of concern and highlights the way in which medical devices of the future will be based on different principles and will deploy different tactics in the search for safe and reliable treatments of disease and injury.
Artificial Organs↗
A prospective study of community-acquired bloodstream infections among febrile adults admitted to Mulago Hospital in Kampala, Uganda.
Septicemia is a frequent cause of death in HIV-infected adults in developing countries. Additional prospective studies are needed to determine the etiology of bloodstream infections (BSI) in febrile HIV-infected adults and guide initial evaluation and treatment in this setting. We assessed the prevalence and etiology of community-acquired BSI among 299 consecutive febrile adult medical admissions to Mulago Hospital, Kampala, Uganda, over a 4-month period in 1997. The median age of our patients was 30 years, 159 (53%) were male, and 227 (76%) HIV-1-seropositive. Overall, prevalence of bacteremia or fungemia (1 patient) was 24%. Bacteremia was more frequent in HIV-infected than in uninfected patients (27% versus 15%, respectively; p = .04). Mycobacterium tuberculosis (n = 28), Streptococcus pneumoniae (n = 15) and Salmonella species (n = 13) were the most frequent isolates. All Salmonella and mycobacterial isolates were recovered from HIV-infected patients. Pneumococcal bacteremia was not associated with HIV seropositivity. M. avium complex and M. simiae were isolated from two HIV-infected patients. The rate of mycobacteremia among febrile HIV-infected adults presenting for hospitalization was 13%. Bacteremia and disseminated tuberculosis are frequent causes of morbidity in febrile HIV-infected Ugandan adults. Initial empiric antibiotic coverage in this setting should be targeted toward the pneumococcus and gram-negative enteric bacilli, especially nontyphi Salmonella species. All patients presenting with chronic cough should be evaluated for tuberculosis.
Adolescent↗
Developing and testing a system to improve the quality of heparin anticoagulation in patients with acute cardiac syndromes.
We have taken a stepwise approach to improving the dosing of continuous intravenous heparin in patients with acute coronary syndromes. Our primary objective was to use computer modeling to develop a nomogram for managing heparin therapy and to put in place a continuous quality monitoring system to evaluate the nomogram's effectiveness. We prospectively collected data on 41 patients with unstable angina or myocardial infarction who were treated with heparin. Their response to heparin was computer modeled and the dose to achieve an activated partial thromboplastin time (aPTT) ratio of 2.0 was established. This dose was regressed against all demographic characteristics to establish predictors of heparin dose (phase I). The regression formula was used prospectively in 110 patients to initiate the infusion rate of heparin and a bolus dose to achieve an aPTT ratio of 2.5. Subsequent dosage adjustments were achieved by computer modeling the patient's aPTT response (phase II). A nomogram was developed that simulated the decisions achieved using computer-assisted methods. This was retrospectively tested and then prospectively tested in 50 patients using nursing staff (phase IV). The nomogram was then made generally available (phase IV) and has been tested in an additional 310 patients. Phase I: Of the original 41 patients, 32% of the aPTT ratios were in the therapeutic range, 36% were supratherapeutic, and 32% were subtherapeutic after the first 24 hours. Phases II and III resulted in 85% of the aPTT ratios between 1.5 and 2.5 at 24 hours. Phase 4 had similar results in 310 patients. The use of computer-assisted or a computer-generated nomogram to adjust heparin therapy results in better control of heparin therapy than using standard methods.
Adult↗
Ligand binding to the (1 --> 3)-beta-D-glucan receptor stimulates NFkappaB activation, but not apoptosis in U937 cells.
Recent data suggest that sepsis stimulates macrophage apoptosis (Ao) with subsequent induction of macrophage dysfunction. Nuclear factor-kappaB (NFkappaB) activation has been linked to Ao in either a pro- or antiapoptotic role. Glucans are biological response modifiers which exert antisepsis activity. This investigation examined the effect of (1-3)-beta-D-glucan receptor binding by a high affinity ligand on Ao and NFkappaB activation in U937 cells in the presence or absence of LPS. A high affinity glucan ligand (IC50 = 23 nM) activated NFkappaB, but did not induce Ao or significantly alter LPS induced U937 Ao. These data indicate that: i) modulation of the macrophage (1-3)-beta-D-glucan receptor stimulates NFkappaB; ii) does not induce Ao or significantly diminish LPS induced Ao and iii) activation of the U937 FAS receptor does not alter the relative Ao responses in glucan and LPS treated cells.
Antibodies↗
Antiproliferative mechanism of action of cryptophycin-52: kinetic stabilization of microtubule dynamics by high-affinity binding to microtubule ends.
Cryptophycin-52 (LY355703) is a new synthetic member of the cryptophycin family of antimitotic antitumor agents that is currently undergoing clinical evaluation. At high concentrations (>/=10 times the IC50), cryptophycin-52 blocked HeLa cell proliferation at mitosis by depolymerizing spindle microtubules and disrupting chromosome organization. However, low concentrations of cryptophycin-52 inhibited cell proliferation at mitosis (IC50 = 11 pM) without significantly altering spindle microtubule mass or organization. Cryptophycin-52 appears to be the most potent suppressor of microtubule dynamics found thus far. It suppressed the dynamic instability behavior of individual microtubules in vitro (IC50 = 20 nM), reducing the rate and extent of shortening and growing without significantly reducing polymer mass or mean microtubule length. Using [3H]cryptophycin-52, we found that the compound bound to microtubule ends in vitro with high affinity (Kd, 47 nM, maximum of approximately 19.5 cryptophycin-52 molecules per microtubule). By analyzing the effects of cryptophycin-52 on dynamics in relation to its binding to microtubules, we determined that approximately 5-6 molecules of cryptophycin-52 bound to a microtubule were sufficient to decrease dynamicity by 50%. Cryptophycin-52 became concentrated in cells 730-fold, and the resulting intracellular cryptophycin-52 concentration was similar to that required to stabilize microtubule dynamics in vitro. The data suggest that cryptophycin-52 potently perturbs kinetic events at microtubule ends that are required for microtubule function during mitosis and that it acts by forming a reversible cryptophycin-52-tubulin stabilizing cap at microtubule ends.
Antineoplastic Agents↗
The impact of psychosocial need and needs resolution on quality of life in patients with brain tumors.
The diagnosis of cancer of the central nervous system (CNS) is often the diagnosis of an incurable, progressive disease with devastating effects on the physical, psychosocial, and cognitive functioning of patients. Because many of the treatment options are noncurative in nature, issues related to quality and quantity of life become paramount. The purpose of the authors' research was to explore the prevalence of psychosocial needs in this cancer population and to determine whether these needs and their resolution impact on quality of life (QOL). Telephone interviews were conducted with 75 patients in whom primary CNS cancer was diagnosed and who were able to pass the Mini-Mental Health Status Examination. Analysis of results indicated that the majority of patients (97.3%) had at least one concern; concerns over treatment side effects, controlling uncertainty, having a meaningful existence, self and body image, and family concerns were among the five most frequently cited need domains. Most patients (91.8%) received help. However, 75.3% reported needing additional help. The number of needs reported and the severity of fatigue most significantly impacted QOL. The study identified the needs and experiences of the patient with CNS cancer. Quality of life and needs assessment information can be used to screen patients for distress and to measure the outcome of medical and psychosocial care and ultimately to ease the burden of illness.
Journal Article↗
Hospital-wide restriction of clindamycin: effect on the incidence of Clostridium difficile-associated diarrhea and cost.
BACKGROUND: Widespread antibiotic use has been associated with increases in both bacterial resistance and nosocomial infection. OBJECTIVE: To characterize the impact of hospital-wide clindamycin restriction on the incidence of Clostridium difficile-associated diarrhea and on antimicrobial prescribing practices. DESIGN: Prospective, observational cohort study. SETTING: University-affiliated Veterans Affairs Medical Center. PATIENTS: Hospitalized patients with symptomatic diarrhea. MEASUREMENTS: Clinical data on individual patients and data on antibiotic use were obtained from hospital pharmacy records. Hospital-wide use of antimicrobial agents was monitored. Isolates of C. difficile underwent antimicrobial susceptibility testing and molecular typing. RESULTS: An outbreak of C. difficile-associated diarrhea was caused by a clonal isolate of clindamycin-resistant C. difficile and was associated with increased use of clindamycin. Hospital-wide requirement of approval by an infectious disease consultant of clindamycin use led to an overall reduction in clindamycin use, a sustained reduction in the mean number of cases of C. difficile-associated diarrhea (11.5 cases/month compared with 3.33 cases/month; P < 0.001), and an increase in clindamycin susceptibility among C. difficile isolates (9% compared with 61%; P < 0.001). A parallel increase was noted in the use of and costs associated with other antibiotics with antianaerobic activity, including cefotetan, ticarcillin-clavulanate, and imipenem-cilastin. The hospital realized overall cost savings as a result of the decreased incidence of C. difficile-associated diarrhea. CONCLUSIONS: Hospital formulary restriction of clindamycin is an effective way to decrease the number of infections due to C. difficile. It can also lead to a return in clindamycin susceptibility among isolates and can effect cost savings to the hospital.
Anti-Bacterial Agents↗